The association between discordant umbilical arterial resistance in growth-restricted fetuses and adverse outcomes.

BACKGROUND: Assessing the umbilical artery pulsatility index via Doppler measurements plays a crucial role in evaluating fetal growth impairment. OBJECTIVE: This study aimed to investigate perinatal outcomes associated with discordant pulsatility indices of umbilical arteries in fetuses with growth restriction. STUDY DESIGN: In this retrospective cohort study, all singleton pregnancies were included if their estimated fetal weight and/or abdominal circumference fell below the 10th percentile for gestational age (2017-2022). Eligible cases included singleton pregnancies with concurrent sampling of both umbilical arteries within 14 days of birth at the ultrasound evaluation closest to delivery. The exclusion criteria included births before 22 weeks of gestation, evidence of absent or reverse end-diastolic flow in either umbilical artery, and known fetal genetic or structural anomalies. The study compared cases with discordant umbilical artery pulsatility index values (defined as 1 umbilical artery pulsatility index at ≤95th percentile and the other umbilical artery pulsatility index at >95th percentile for gestational age) to pregnancies where both umbilical artery pulsatility indices had normal pulsatility index values and those with both umbilical arteries displaying abnormal pulsatility index values. The primary outcome assessed was the occurrence of composite adverse neonatal outcomes. Multivariable logistic regressions were performed, adjusting for relevant covariates. RESULTS: The study encompassed 1014 patients, including 194 patients (19.1%) with discordant umbilical artery pulsatility index values among those who had both umbilical arteries sampled close to delivery, 671 patients (66.2%) with both umbilical arteries having normal pulsatility index values, and 149 patients (14.7%) with both umbilical arteries exhibiting abnormal values. Pregnancies with discordant umbilical artery pulsatility index values displayed compromised sonographic parameters compared with those with both umbilical arteries showing normal pulsatility index values. Similarly, the number of abnormal umbilical artery pulsatility index values was associated with adverse perinatal outcomes in a dose-response manner. Cases with 1 abnormal (discordant) umbilical artery pulsatility index value showed favorable sonographic parameters and perinatal outcomes compared with cases with both abnormal umbilical artery pulsatility index values, and cases with both abnormal umbilical artery pulsatility index values showed worse sonographic parameters and perinatal outcomes compared with cases with discordant UA PI values. Multivariate analysis revealed that discordant umbilical artery pulsatility indices were significantly and independently associated with composite adverse perinatal outcomes, with an adjusted odds ratio of 1.75 (95% confidence interval, 1.24-2.47; P = .002). CONCLUSION: Evaluating the resistance indices of both umbilical arteries may provide useful data and assist in assessing adverse perinatal outcomes among fetuses with growth restriction.

Effect of maternal hyperoxygenation on neonatal outcomes among women in labour with pathological cardiotocography: an open-label randomized controlled trial.

BACKGROUND: Hyperoxygenation has shown promise in improving suspicious fetal heart patterns in women in labor. However, the effect of hyperoxygenation on neonatal outcomes in women in labor with pathologic fetal heart rate tracing has not been studied. OBJECTIVE: This study aimed to evaluate the effect of fractional inspiration of oxygen of 80% compared with fractional inspiration of oxygen of 40% on neonatal outcomes in women with pathologic fetal heart rate tracing. STUDY DESIGN: This randomized, open-label, parallel arm, outcome assessor-blinded clinical trial was conducted in a large tertiary care university hospital. Singleton parturients aged ≥18 years at term gestation in active labor (cervical dilatation of ≥6 cm) with pathologic fetal heart rate tracing were recruited in the study. Pathologic fetal heart rate tracing was defined according to the International Federation of Gynecology and Obstetrics 2015 guidelines. The International Federation of Gynecology and Obstetrics classifies fetal heart rate tracings into 3 categories (normal, suspicious, and pathologic) based on rate, variability, and deceleration. Women in the intervention arm received oxygen at 10 L/min via a nonrebreathing mask, and those in the usual care arm received oxygen at 6 L/min with a simple face mask. Oxygen supplementation was continued until cord clamping. The primary outcome measure was a 5-minute Apgar score. The secondary outcome measures were the proportion of neonatal intensive care unit admission, umbilical cord blood gas variables, level of methyl malondialdehyde in the cord blood, and mode of delivery. RESULTS: Overall, 148 women (74 women in the high fractional inspiration of oxygen arm and 74 in the low fractional inspiration of oxygen arm) with pathologic fetal heart rate tracing were analyzed. The demographic data, obstetrical profiles, and comorbidities were comparable. The median 5-minute Apgar scores were 9 (interquartile range, 8-10) in the hyperoxygenation arm and 9 (interquartile range, 8-10) in the usual care arm (P=.12). Furthermore, the rate of neonatal intensive care unit admission (9.5% vs 12.2%; P=.6) and the requirement of positive pressure ventilation (6.8% vs 8.1%; P=.75) were comparable. Concerning cord blood gas parameters, the hyperoxygenation arm had a significantly higher base deficit in the umbilical vein and lactate level in the umbilical artery. The cesarean delivery rate was significantly lower in women who received hyperoxygenation (4.1% [3/74]) than in women who received normal oxygen supplementation (25.7% [19/74]) (P=.00). In addition, umbilical vein malondialdehyde level in the umbilical vein was lower in the hyperoxygenation group (8.28±4.65 µmol/L) than in the normal oxygen supplementation group (13.44±8.34 µmol/L) (P=.00). CONCLUSION: Hyperoxygenation did not improve the neonatal Apgar score in women with pathologic fetal heart rate tracing. In addition, neonatal intensive care unit admission rate and blood gas parameters remained comparable. Therefore, the results of this trial suggest that a high fractional inspiration of oxygen supplementation confers no benefit on neonatal outcomes in women with pathologic fetal heart rate tracings and normal oxygen saturation.

Placental differences between severe fetal growth restriction and hypertensive disorders of pregnancy requiring early preterm delivery: morphometric analysis of the villous tree supported by artificial intelligence.

BACKGROUND: The great obstetrical syndromes of fetal growth restriction and hypertensive disorders of pregnancy can occur individually or be interrelated. Placental pathologic findings often overlap between these conditions, regardless of whether 1 or both diagnoses are present. Quantification of placental villous structures in each of these settings may identify distinct differences in developmental pathways. OBJECTIVE: This study aimed to determine how the quantity and surface area of placental villi and vessels differ between severe, early-onset fetal growth restriction with absent or reversed umbilical artery Doppler indices and hypertensive disorders of pregnancy or the 2 conditions combined among subjects with disease severity that warrant early preterm delivery. We hypothesized that the trajectories of placental morphogenesis diverge after a common initiating insult of deep defective placentation. Specifically, we postulated that only villi are affected in pregnancy-related hypertension, whereas both villous and vascular structures are proportionally diminished in severe fetal growth restriction with no additional effect when hypertension is concomitantly present. STUDY DESIGN: In this retrospective cohort study, paraffin-embedded placental tissue was obtained from 4 groups, namely (1) patients with severe fetal growth restriction with absent or reversed umbilical artery end-diastolic velocities and hypertensive disorders of pregnancy, (2) patients with severe fetal growth restriction with absent or reversed umbilical artery Doppler indices and no hypertension, (3) gestational age-matched, appropriately grown pregnancies with hypertensive disease, and (4) gestational age-matched, appropriately grown pregnancies without hypertension. Dual immunohistochemistry for cytokeratin-7 (trophoblast) and CD34 (endothelial cells) was performed, followed by artificial intelligence-driven morphometric analyses. The number of villi, total villous area, number of fetoplacental vessels, and total vascular area across villi within a uniform region of interest were quantified. Quantitative analyses of placental structures were modeled using linear regression. RESULTS: Placentas from pregnancies complicated by hypertensive disorders of pregnancy exhibited significantly fewer stem villi (-282 stem villi; 95% confidence interval, -467 to -98; P<.01), a smaller stem villous area (-4.3 mm2; 95% confidence interval, -7.3 to -1.2; P<.01), and fewer stem villous vessels (-4967 stem villous vessels; 95% confidence interval, -8501 to -1433; P<.01) with no difference in the total vascular area. In contrast, placental abnormalities in cases with severe growth restriction were limited to terminal villi with global decreases in the number of villi (-873 terminal villi; 95% confidence interval, -1501 to -246; P<.01), the villous area (-1.5 mm2; 95% confidence interval, -2.7 to -0.4; P<.01), the number of blood vessels (-5165 terminal villous vessels; 95% confidence interval, -8201 to -2128; P<.01), and the vascular area (-0.6 mm2; 95% confidence interval, -1.1 to -0.1; P=.02). The combination of hypertension and growth restriction had no additional effect beyond the individual impact of each state. CONCLUSION: Pregnancies complicated by hypertensive disorders of pregnancy exhibited defects in the stem villi only, whereas placental abnormalities in severely growth restricted pregnancies with absent or reversed umbilical artery end-diastolic velocities were limited to the terminal villi. There were no significant statistical interactions in the combination of growth restriction and hypertension, suggesting that distinct pathophysiological pathways downstream of the initial insult of defective placentation are involved in each entity and do not synergize to lead to more severe pathologic consequences. Delineating mechanisms that underly the divergence in placental development after a common inciting event of defective deep placentation may shed light on new targets for prevention or treatment.

Maternal rest improves growth in small-for-gestational-age fetuses (<10th percentile).

BACKGROUND: Optimal management of fetuses diagnosed as small for gestational age based on an estimated fetal weight of <10th percentile represents a major clinical problem. The standard approach is to increase fetal surveillance with serial biometry and antepartum testing to assess fetal well-being and timing of delivery. Observational studies have indicated that maternal rest in the left lateral position improves maternal cardiac output and uterine blood flow. However, maternal bed rest has not been recommended based on the results of a randomized clinical trial that showed that maternal rest does not improve fetal growth in small-for-gestational-age fetuses. This study was conducted to revisit this question. OBJECTIVE: This study aimed to determine whether maternal bed rest was associated with an increase in the fetal biometric parameters that reflect growth after the diagnosis of a small-for-gestational-age fetus. STUDY DESIGN: A retrospective study was conducted on fetuses who were diagnosed as small for gestational age because of an estimated fetal weight of <10th percentile for gestational age. The mothers were asked to rest in the left lateral recumbent position. Fetal biometry was performed 2 weeks after the diagnosis. All fetuses before entry into the study had a previous ultrasound that demonstrated an estimated fetal weight of >10th percentile. To assess the response to bed rest, the change in fetal biometric parameters (estimated fetal weight, head circumference, abdominal circumference, and femur length) after the recommendation of bed rest was computed for 2 periods: (1) before the diagnosis of a weight of <10th percentile vs at the time of diagnosis of a weight of <10th percentile and (2) at the time of diagnosis of a weight of <10th percentile vs 2 weeks after maternal bed rest. For repeated measures, proportions were compared using the McNemar test, and percentile values were compared using the Kruskal-Wallis test. A P value of <.05 was considered significant. To describe changes in the estimated fetal weight without bed rest, 2 control groups in which the mothers were not placed on bed rest after the diagnosis of a small-for-gestational-age fetus were included. RESULTS: A total of 265 fetuses were observed before and after maternal bed rest. The following were observed in this study: (1) after 2 weeks of maternal rest, 199 of 265 fetuses (75%) had a fetal weight of >10th percentile; (2) the median fetal weight percentile increased from 6.8 (interquartile range, 4.4-8.4) to 18.0 (interquartile range, 9.5-29.5) after 2 weeks of bed rest; (3) similar trends were noted for the head circumference, abdominal circumference, and femur length. In the groups of patients who were not asked to be on bed rest, a reassignment to a weight of >10th percentile at a follow-up examination only occurred in 7 of 37 patients (19%) in the Texas-Michigan group and 13 of 111 patients (12%) in the Colorado group compared with the bed rest group (199/265 [75%]) (P<.001). CONCLUSION: Patients who were prescribed 2 weeks of bed rest after the diagnosis of a fetal weight of <10th percentile had an increase in weight of >10th percentile in 199 of 265 fetuses (75%). This increase in fetal weight was significantly higher than that in the 2 control groups in which bed rest was not prescribed. This observation suggests that bed rest improves fetal growth in a subset of patients.

Risk factors associated with stillbirth and adverse perinatal outcomes in dichorionic twin pregnancies complicated by selective fetal growth restriction: a cohort study.

OBJECTIVE: The main aim of this study was to investigate the perinatal outcomes of dichorionic twin pregnancies complicated by selective fetal growth restriction (sFGR). DESIGN: Retrospective cohort study. SETTING: Tertiary reference centre. POPULATION: Dichorionic twin pregnancies complicated by sFGR between 2000 and 2019 in St George's University Hospital. METHODS: Regression analyses were performed using generalised linear models and mixed-effects generalised linear models where appropriate to account for pregnancy level dependency in variables. Time to event analyses were performed with mixed-effects Cox regression models. MAIN OUTCOME MEASURES: Stillbirth, neonatal death or neonatal unit admission with morbidity in one or both twins. RESULTS: A total of 102 (of 2431 dichorionic twin pregnancies) pregnancies complicated by sFGR were included in the study. The Cochrane-Armitage test revealed a significant trend for increased adverse perinatal outcome rates with more severe forms of umbilical artery flow impedance, i.e. reversed, absent, positive with resistant flow and positive flow without resistance. A multivariable model including maternal and conception characteristics had poor predictive accuracy for stillbirth (area under the curve: 0.68, 95% confidence interval [CI] 0.55-0.81) and composite adverse perinatal outcomes (area under the curve: 0.58, 95% CI 0.47-0.70). When umbilical artery Doppler parameters were added to the models, the area under the curve values improved to 0.95 (95% CI 0.89-0.99) and 0.83 (95% CI 0.73-0.92) for stillbirth and composite adverse perinatal outcomes, respectively. CONCLUSION: In dichorionic twin pregnancies complicated by sFGR, the umbilical artery Z-scores were associated with both intrauterine death and adverse perinatal outcomes.

Assessment of fetal growth trajectory identifies infants at high risk of perinatal mortality.

OBJECTIVE: To analyze perinatal risks associated with three distinct scenarios of fetal growth trajectory in the latter half of pregnancy compared with a reference group. METHODS: This cohort study included women with a singleton pregnancy that delivered between 32 + 0 and 41 + 6 weeks' gestation and had two or more ultrasound scans, at least 4 weeks apart, from 18 + 0 weeks. We evaluated three different scenarios of fetal growth against a reference group, which comprised appropriate-for-gestational-age fetuses with appropriate forward-growth trajectory. The comparator growth trajectories were categorized as: Group 1, small-for-gestational-age (SGA) fetuses (estimated fetal weight (EFW) or abdominal circumference (AC) persistently < 10th centile) with appropriate forward growth; Group 2, fetuses with decreased growth trajectory (decrease of ≥ 50 centiles) and EFW or AC ≥ 10th centile (i.e. non-SGA) at their final ultrasound scan; and Group 3, fetuses with decreased growth trajectory and EFW or AC < 10th centile (i.e. SGA) at their final scan. The primary outcome was overall perinatal mortality (stillbirth or neonatal death). Secondary outcomes included stillbirth, delivery of a SGA infant, preterm birth, emergency Cesarean section for non-reassuring fetal status and composite severe neonatal morbidity. Associations were analyzed using logistic regression. RESULTS: The final study cohort comprised 5319 pregnancies. Compared to the reference group, the adjusted odds of perinatal mortality were increased significantly in Group 2 (adjusted odds ratio (aOR), 4.00 (95% CI, 1.36-11.22)) and Group 3 (aOR, 7.71 (95% CI, 2.39-24.91)). Only Group 3 had increased odds of stillbirth (aOR, 5.69 (95% CI, 1.55-20.93)). In contrast, infants in Group 1 did not have significantly increased odds of demise. The odds of a SGA infant at birth were increased in all three groups compared with the reference group, but was highest in Group 1 (aOR, 111.86 (95% CI, 62.58-199.95)) and Group 3 (aOR, 40.63 (95% CI, 29.01-56.92)). In both groups, more than 80% of infants were born SGA and nearly half had a birth weight < 3rd centile. Likewise, the odds of preterm birth were increased in all three groups compared with the reference group, being highest in Group 3, with an aOR of 4.27 (95% CI, 3.23-5.64). Lastly, the odds of composite severe neonatal morbidity were increased in Groups 1 and 3, whereas the odds of emergency Cesarean section for non-reassuring fetal status were increased only in Group 3. CONCLUSION: Assessing the fetal growth trajectory in the latter half of pregnancy can help identify infants at increased risk of perinatal mortality and birth weight < 3rd centile for gestation. © 2024 International Society of Ultrasound in Obstetrics and Gynecology.

Single Umbilical Artery Umbilical Cord Is Associated With High-Grade Distal Fetal Vascular Malperfusion.

PURPOSE AND CONTEXT: Umbilical cord abnormalities with clinical signs of cord compromise are frequently associated with fetal vascular malperfusion (FVM). Single umbilical artery (SUA) has been reported to be associated with high-grade FVM in fetal growth restriction but not in an unselected population; our study aimed to address this issue. METHODS: Clinical and placental phenotypes of 55 consecutive placentas with SUA (Group 1) were compared with those of 655 placentas with 3-vessel umbilical cord (Group 2) from patients who were in the second half of their pregnancy. The placentas were histologically examined using hematoxylin and eosin (H&E) staining and CD 34 immunostaining. KEY RESULTS: Several umbilical cord phenotypes and high-grade distal FVM, based on H&E staining and endothelial fragmentation by CD34 were significantly more common in Group 1, whereas decidual clusters of multinucleate trophoblasts were more common in Group 2. Notably, H&E staining or CD34 immunostaining evaluated separately showed that high-grade distal FVM was more common in Group 1 than in Group 2, but the difference was not statistically significant. CONCLUSIONS: SUA predisposes to remote, advanced, and recent high-grade distal villous FVM, with a pathogenesis partly different from that of stasis-induced FVM, likely related to fetal anomalies associated with SUA.

Absence of Ductus Venosus: A Comparison of 2 Distinctive Fetal Autopsy Cases and Embryologic Perspectives.

In fetal circulation, oxygenated blood from the placenta flows through the umbilical vein into the ductus venosus (DV), then enters the inferior vena cava, and subsequently reaches the right atrium of the heart. The DV serves as a shunt, allowing this oxygen-rich blood to bypass the liver. The absence of the DV (ADV), also known as agenesis of the DV, is a rare congenital anomaly. Without a DV, blood from the umbilical vein must follow alternative routes to the heart. In ADV cases, blood from the umbilical vein must follow 1 of 2 primary drainage patterns: either an extrahepatic shunt or an intrahepatic shunt. This report details the antenatal ultrasound and postmortem findings of 2 fetuses diagnosed with ADV by prenatal imaging studies. The first case involved a fetus with a persistent right umbilical vein connected directly to the suprahepatic IVC, accompanied by early obliteration of the left umbilical vein and true agenesis of the DV. This fetus also had additional congenital anomalies. In contrast, the second case involved a fetus with a normal left umbilical vein that entered the liver. However, despite an ultrasound diagnosis of "absence" of the DV, a DV was present, though markedly hypoplastic and probably minimally functional or non-functional. In this case, blood from the umbilical vein likely followed an alternate intrahepatic route through the portal and hepatic veins, before reaching the heart (intrahepatic shunt). These contrasting cases emphasize the heterogeneity of vascular anomalies and embryologic origins captured by the term "ADV." Additionally, the terminology of "absence" or "agenesis" may be misleading in some purported ADV cases. Specifically, in the second case, the DV was not absent; it was markedly hypoplastic instead. This also appears to be the first reported case of a hypoplastic DV in a fetus. Both cases underscore the importance of effective collaboration and clear communication between maternal-fetal medicine specialists and pathologists.

Umbilical artery thrombosis risk factors and perinatal outcomes.

PURPOSE: The purpose of this study was to investigate the risk factors for umbilical artery thrombosis (UAT) and the relationship between umbilical artery thrombosis and perinatal outcomes. METHODS: This was a retrospective study that enrolled singleton pregnant women who were diagnosed with umbilical artery thrombosis. The control group recruited pregnant woman with three umbilical vessels or those with isolated single umbilical artery (iSUA) who were matched with umbilical artery thrombosis group. The risk factors and perinatal outcomes were compared between the groups. RESULTS: Preconception BMI (OR [95%CI]: 1.212 [1.038-1.416]), abnormal umbilical cord insertion (OR [95%CI]: 16.695 [1.333-209.177]) and thrombophilia (OR [95%CI]: 15.840 [1.112-223.699]) were statistically significant risk factors for umbilical artery thrombosis. An elongated prothrombin time (OR [95%CI]: 2.069[1.091-3.924]) was strongly associated with the occurrence of UAT. The risks of cesarean delivery, preterm birth, fetal growth restriction, neonatal asphyxia, and intraamniotic infection were higher in pregnancies with UAT than in pregnancies with three umbilical vessels or isolated single umbilical artery (P<0.05). Additionally, the incidence of thrombophilia was higher in pregnant women with umbilical artery thrombosis than those with isolated single umbilical artery (P = 0.032). Abnormal umbilical cord insertion was also found to be associated with an elevated risk of iSUA (OR [95%CI]: 15.043[1.750-129.334]). CONCLUSIONS: Abnormal umbilical cord insertion was the risk factor for both umbilical artery thrombosis and isolated single umbilical artery. The pregnancies with umbilical artery thrombosis had a higher risk of the adverse perinatal outcomes.

Diagnosis of single umbilical artery and risk of foetal congenital malformations by prenatal ultrasound: a retrospective study.

BACKGROUND: Single umbilical artery (SUA) is strongly associated with foetal structural abnormalities; however, the exact pattern of this association has not been described. We aimed to investigate the occurrence of malformations in singleton pregnancies with SUA in China and to study the association between the absent side of the umbilical artery and foetal malformations. METHODS: This was a retrospective study of singleton pregnancies for which routine first-trimester anatomical screening was performed at 11+ 0-13+ 6 gestational weeks and, if the pregnancy continued, a second-trimester scan was performed at 20+ 0-24+ 0 weeks. Data were extracted from records at the referral centre, the Obstetrics and Gynecology Hospital of Fudan University, between January 2011 and April 2019 (n = 47,894). Using logistic regression, the odds ratios (OR) with 95% confidence intervals (CIs) were calculated for malformations associated with SUA. RESULTS: The incidence of SUA in our study was 2.0% (970/47,894). Of all foetuses with SUA, 387 (39.9%) had structural malformations. The malformation type varied, with cardiovascular complications being the most common. A robust association was observed between SUA and oesophageal stenosis or atresia (OR: 25.33), followed by cardiovascular (OR: 9.98-24.02), scoliosis (OR: 18.62), genitourinary (OR: 2.45-15.66), and brain malformations (OR: 4.73-9.12). The absence of the left umbilical artery (n = 445, 45.9%) was consistent with that of the right umbilical artery (n = 431, 44.4%). Furthermore, a significantly higher rate of an absent right than the left umbilical artery (p<0.01) was observed in SUA with foetal abnormalities than in SUA with no malformations. CONCLUSIONS: Overall, we observed a higher risk of various specific malformations in foetuses with SUA, and a strong association between SUA and oesophageal stenosis or atresia. The absence of the right umbilical artery was most common in foetuses with SUA and structural malformations. This study provides a reference for ultrasonographers in conducting foetal structural screening for pregnant women with SUA.

A case report of single umbilical artery combined with fetal bladder exstrophy in singleton pregnancy and related literature review.

BACKGROUND: According to prenatal ultrasonographic studies, single umbilical artery may be present alone or in association with other fetal abnormalities. So far, the exact pathogenesis of bladder exstrophy is unclear. Some scholars believe that bladder exstrophy and cloacal exstrophy should be regarded as a disease spectrum to explore their pathogenesis. If bladder exstrophy and cloacal exstrophy are regarded as the same disease spectrum, then we can speculate that the single umbilical artery should have the probability of being accompanied by bladder exstrophy at the same time. CASE PRESENTATION: For the first time, we report a rare case of fetal bladder exstrophy with single umbilical artery in single pregnancy. This patient underwent targeted color Doppler ultrasound at 26 weeks of pregnancy which first suspected bladder exstrophy with single umbilical artery and fetal MRI for diagnosis at 38 + 3 weeks of pregnancy which confirmed the suspicion. After the diagnosis was confirmed, the patient was scheduled for a multidisciplinary discussion. Ultimately the patient opted for induced fetal demise at 38 + 5 weeks of pregnancy and the physical appearance of the fetal demise affirmed previous ultrasound and MRI examination results. CONCLUSIONS: Our report is the first finding of single umbilical artery combined with bladder exstrophy in a singleton pregnancy. Accordingly, our case enhances the evidence that cloacal exstrophy and bladder exstrophy should be treated as the same disease spectrum. In addition, we conducted a literature review on the diagnostic progress of single umbilical artery combined with bladder exstrophy, hoping to provide useful references for the diagnosis of this disease.

Uterine contractile activity and neonatal outcome - A blind analysis of a randomized controlled trial cohort.

INTRODUCTION: Sufficient contractions are necessary for a successful delivery but each contraction temporarily constricts the oxygenated blood flow to the fetus. Individual fetal or placental characteristics determine how the fetus can withstand this temporary low oxygen saturation. However, only a few studies have examined the impact of uterine activity on neonatal outcome and even less attention has been paid to parturients' individual characteristics. Our objective was therefore to find out whether fetuses compromised by maternal or intrapartum risk factors are more vulnerable to excessive uterine activity. MATERIAL AND METHODS: Uterine contractile activity was assessed by intrauterine pressure catheters. Women (n = 625) with term singleton pregnancies and fetus in cephalic presentation were included in this secondary, blind analysis of a randomized controlled trial cohort. Intrauterine pressure as Montevideo units (MVU), contraction frequency/10 min and uterine baseline tone were calculated for 4 h prior to birth or the decision to perform cesarean section. Uterine activity in relation to umbilical artery pH linearly or ≤7.10 was used as the primary outcome. Need for operative delivery (either cesarean section or vacuum-assisted delivery) due to fetal distress was analyzed as a secondary outcome. In addition, belonging to vulnerable subgroups with, for example, chorioamnionitis, hypertensive or diabetic disorders, maternal smoking or neonatal birthweight <10th percentile were investigated as additional risk factors. RESULTS: A linear decline in umbilical artery pH was seen with increasing intrauterine pressure in all deliveries (p < 0.001). Among parturients with suspected chorioamnionitis, every increasing 10 MVUs increased the likelihood of umbilical artery pH ≤7.10 (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.02-1.34, p = 0.023). The need for operative delivery due to fetal distress was increased among all laboring women by every increasing 10 MVUs (OR 1.05, 95% CI 1.01-1.09, p = 0.015). This association with operative deliveries was further increased among parturients with hypertensive disorders (OR 1.23, 95% CI 1.05-1.43, p = 0.009) and among those with diabetic disorders (OR 1.13, 95% CI 1.04-1.28, p = 0.003). CONCLUSIONS: Increasing intrauterine pressure impairs umbilical artery pH especially among parturients with suspected chorioamnionitis. Fetuses in pregnancies affected by chorioamnionitis, hypertensive or diabetic disorders are more vulnerable to high intrauterine pressure.

The impact of late pregnancy dating on the detection of fetal growth restriction at term.

INTRODUCTION: The inaccuracy of late pregnancy dating is often discussed, and the impact on diagnosis of fetal growth restriction is a concern. However, the magnitude and direction of this effect has not previously been demonstrated. In this study, we aimed to investigate the effect of late pregnancy dating by head circumference on the detection of late onset growth restriction, compared to first trimester crown-rump length dating. MATERIAL AND METHODS: This was a cohort study of 14 013 pregnancies receiving obstetric care at a tertiary center over a three-year period. Universal scans were performed at 12 weeks, including crown-rump length; at 20 weeks including fetal biometry; and at 36 weeks, where biometry, umbilical artery doppler and cerebroplacental ratio were used to determine the incidence of fetal growth restriction according to the Delphi consensus. For the entire cohort, the gestational age was first calculated using T1 dating; and was then recalculated using head circumference at 20 weeks (T2 dating); and at 36 weeks (T3 dating). The incidence of fetal growth restriction following T2 and T3 dating was compared to T1 dating using four-by-four sensitivity tables. RESULTS: When the cohort was redated from T1 to T2, the median gestation at delivery changed from 40 + 0 to 40 + 2 weeks (p < 0.001). When the cohort was redated from T1 to T3, the median gestation at delivery changed from 40 + 0 to 40 + 3 weeks (p < 0.001). T2 dating resulted in fetal growth restriction sensitivity of 80.2% with positive predictive value of 78.8% compared to T1 dating. T3 dating resulted in sensitivity of 8.6% and positive predictive value of 27.7%, respectively. The sensitivity of abnormal CPR remained high despite T2 and T3 redating; 98.0% and 89.4%, respectively. CONCLUSIONS: Although dating at 11-14 weeks is recommended, late pregnancy dating is sometimes inevitable, and this can prolong the estimated due date by an average of two to three days. One in five pregnancies which would be classified as growth restricted if the pregnancy was dated in the first trimester, will be reclassified as nongrowth restricted following dating at 20 weeks, whereas nine out of 10 pregnancies will be reclassified as non-growth restricted with 36-week dating.

Management of fetuses with apparent normal growth and abnormal cerebroplacental ratio: A risk-based approach near term.

INTRODUCTION: Cerebroplacental ratio (CPR) has been shown to be an independent predictor of adverse perinatal outcome at term and a marker of failure to reach the growth potential (FRGP) regardless of fetal size, being abnormal in compromised fetuses with birthweight above the 10th centile. The main aim of this study was to propose a risk-based approach for the management of pregnancies with normal estimated fetal weight (EFW) and abnormal CPR near term. MATERIAL AND METHODS: This was a retrospective study of 943 pregnancies, that underwent an ultrasound evaluation of EFW and CPR at or beyond 34 weeks. CPR values were converted into multiples of the median (MoM) and EFW into centiles according to local references. Pregnancies were then divided into four groups: normal fetuses (defined as EFW ≥10th centile and CPR ≥0.6765 MoM), small for gestational age (EFW <10th centile and CPR ≥0.6765 MoM), fetal growth restriction (EFW <10th centile and CPR <0.6765 MoM), and fetuses with apparent normal growth (EFW ≥10th centile) and abnormal CPR (<0.6765 MoM), that present FRGP. Intrapartum fetal compromise (IFC) was defined as an abnormal intrapartum cardiotocogram or pH requiring cesarean delivery. Risk comparisons were performed among the four groups, based on the different frequencies of IFC. The risks of IFC were subsequently extrapolated into a gestational age scale, defining the optimal gestation to plan the birth for each of the four groups. RESULTS: Fetal growth restriction was the group with the highest frequency of IFC followed by FRGP, small for gestational age, and normal groups. The "a priori" risks of the fetal growth restriction and normal groups were used to determine the limits of two scales. One defining the IFC risk and the other defining the appropriate gestational age for delivery. Extrapolation of the risk between both scales placed the optimal gestational age for delivery at 39 weeks of gestation in the case of FRGP and at 40 weeks in the case of small for gestational age. CONCLUSIONS: Fetuses near term may be evaluated according to the CPR and EFW defining four groups that present a progressive risk of IFC. Fetuses in pregnancies complicated by FRGP are likely to benefit from being delivered at 39 weeks of gestation.

Development of Artificial Intelligence Image Classification Models for Determination of Umbilical Cord Vascular Anomalies.

OBJECTIVE: The goal of this work was to develop robust techniques for the processing and identification of SUA using artificial intelligence (AI) image classification models. METHODS: Ultrasound images obtained retrospectively were analyzed for blinding, text removal, AI training, and image prediction. After developing and testing text removal methods, a small n-size study (40 images) using fastai/PyTorch to classify umbilical cord images. This data set was expanded to 286 lateral-CFI images that were used to compare: different neural network performance, diagnostic value, and model predictions. RESULTS: AI-Optical Character Recognition method was superior in its ability to remove text from images. The small n-size mixed single umbilical artery determination data set was tested with a pretrained ResNet34 neural network and obtained and error rate average of 0.083 (n = 3). The expanded data set was then tested with several AI models. The majority of the tested networks were able to obtain an average error rate of <0.15 with minimal modifications. The ResNet34-default performed the best with: an image-classification error rate of 0.0175, sensitivity of 1.00, specificity of 0.97, and ability to correctly infer classification. CONCLUSION: This work provides a robust framework for ultrasound image AI classifications. AI could successfully classify umbilical cord types of ultrasound image study with excellent diagnostic value. Together this study provides a reproducible framework to develop AI-specific ultrasound classification of umbilical cord or other diagnoses to be used in conjunction with physicians for optimal patient care.

A Pilot Study of Ultrasound Assessment of Umbilical Cord and Placental Vascular Flow for Cord Accident Stillbirth Prevention.

OBJECTIVE: Our objective was to determine the feasibility and interobserver reliability of umbilical cord and placental arteriolar flow assessment in low-risk pregnancies near term. METHODS: This was a prospective pilot study in low-risk pregnancies at 36 weeks with anterior placentas. We excluded any with an indication for antenatal testing or delivery before 39 weeks. Each participant underwent two ultrasounds by different examiners, which included arterial and venous velocimetry at three cord sites (fetal, free loop, and placental) in addition to maternal and fetal placental arterioles. The interobserver reliability was quantified using the Pearson correlation coefficient with that of standard clinical parameters serving as a benchmark for interpretation. RESULTS: Among 53 participants scanned at 356/7-371/7 weeks, the mean examination duration was 20.5 ± 4.2 minutes. Ascertainment success was high for measures at the free loop, placental cord insertion, and fetal placental arterioles (range 90.6%-99.1%) and was lower at the fetal cord insertion and maternal spiral arterioles (range 47.2%-87.7%). Interobserver reliability estimates for free-loop systolic/diastolic and pulsatility index ranged from 0.38 to 0.44. Interobserver reliability for experimental parameters varied by measurement site, and all were poor at the fetal insertion and in placental arterioles. Parameters had significant variation across cord sites (range 4.3%-21.7%). CONCLUSION: In our cohort, flow assessments of the free loop, placental insertion, and placental arterioles are feasible, but interrater reliability varies by measurement type and cord site. Future studies are needed to establish feasibility and reliability in nonanterior placentation and to assess clinical relevance.

The changing Doppler patterns and perinatal outcomes of monochorionic diamniotic twins with selective fetal growth restriction.

OBJECTIVES: To investigate the clinical outcomes and Doppler patterns changes in monochorionic diamniotic (MCDA) twins with selective fetal growth restriction (sFGR). METHODS: We retrospectively analyzed 362 sFGR cases from January 2010 to May 2016 at a single tertiary referral center. The Doppler waveforms of umbilical artery end-diastolic flow were collected, and all neonates were subjected to an early neonatal brain scan. RESULTS: A total of 66/100 (66 %) type I cases were stable, whereas 25/100 (25 %) cases changed to type II and 9/100 (9 %) changed to sFGR complicated twin-twin transfusion syndrome (TTTS). A total of 48.9 % (22/45) sFGR cases were complicated with polyhydramnios and 30.4 % (7/23) sFGR cases were complicated with oligohydramnios, both of which were progressed to sFGR with TTTS. Mild cerebral injury was significantly associated with Doppler flow abnormalities, earlier gestational age at delivery and type of sFGR diagnosis. Severe cerebral injury was significantly associated with gestational age at delivery (31.6 vs. 34.1, p=0.002) and larger birthweight discordance (43.9 vs. 29.3 %, p=0.011). CONCLUSIONS: Doppler patterns in sFGR can gradually change, with important consequences with regard to management and outcomes. Along with abnormal Doppler findings, earlier occurrence of sFGR and delivery are associated with subsequent neonatal cerebral injury.

Association of low pregnancy associated plasma protein-A with increased umbilical artery pulsatility index in cases of fetal weight between the 3rd and 10th percentiles: a retrospective cohort study.

OBJECTIVES: This study aims to evaluate if low levels of serum maternal pregnancy associated plasma protein-A (PAPP-A) during the first trimester are related to increased umbilical artery pulsatility index (UA PI) later in pregnancy, in cases of estimated fetal weight between the 3rd and 10th percentiles, in order to establish PAPP-A as a predictor of this particular cases of fetal growth restriction (FGR). METHODS: An observational, retrospective cohort study, conducted at a tertiary University Hospital located in Oporto, Portugal. Pregnant women who did the first trimester combined screening, between May 2013 and June 2020 and gave birth in the same hospital, with an estimated fetal weight (EFW) between the 3rd and 10th percentiles were included. The primary outcome is the difference in increased UA PI prevalence between two groups: PAPP-A<0.45 MoM and PAPP-A≥0.45 MoM. As secondary outcomes were evaluated differences in neonatal weight, gestational age at delivery, cesarean delivery, neonatal intensive care unit hospitalization, 5-min Apgar score below 7 and live birth rate between the same two groups. RESULTS: We included 664 pregnancies: 110 cases of PAPP-A<0.45 MoM and 554 cases with PAPP-A≥0.45 MoM. Increased UA PI prevalence, which was the primary outcome of this study, was significantly different between the two groups (p=0.005), as the PAPP-A<0.45 MoM group presents a higher prevalence (12.7 %) when compared to the PAPP-A≥0.45 MoM group (5.4 %). The secondary outcome cesarean delivery rate was significantly different between the groups (p=0.014), as the PAPP-A<0.45 MoM group presents a higher prevalence (42.7 %) than the PAPP-A≥0.45 MoM group (30.1 %). No other secondary outcomes showed differences between the two groups. CONCLUSIONS: There is an association of low serum maternal PAPP-A (<0.45 MoM) during the first trimester and increased UA PI (>95th percentile) later in pregnancy, in cases of EFW between the 3rd and 10th percentiles. However, this association is not strong enough alone for low PAPP-A to be a reliable predictor of increased UA PI in this population.

Perinatal outcomes according to umbilical artery Doppler assessment among fetuses with congenital heart disease.

PURPOSE: To evaluate a cohort of fetuses with congenital heart disease (CHD) who underwent serial umbilical artery (UA) Doppler surveillance and assess perinatal outcome according to UA Doppler assessment. METHODS: A retrospective cohort study of singleton fetuses with CHD at a single academic center was performed between 2018 and 2020. Fetuses with a chromosomal abnormality or growth restriction were excluded. We compared fetuses with normal versus abnormal UA Doppler assessment at any time in pregnancy. Abnormal UA Doppler assessment was defined as decreased end diastolic flow, determined by an elevated systolic/diastolic ratio >95th percentile for gestational age, or absent/reversed end diastolic flow. Logistic regression assessed the odds of fetuses with CHD and abnormal UA Doppler assessment having a composite adverse perinatal (defined as fetal, neonatal, or infant death), adjusting for relevant covariates. RESULTS: We identified a cohort of 171 fetuses with CHD that met inclusion criteria. Of these, 154 (90%) had normal UA Doppler assessment and 17 (10%) had abnormal UA Doppler assessment throughout pregnancy. Maternal characteristics did not differ between groups except for maternal race and history of preeclampsia. There was no statistically significant difference in primary outcome between groups [14% (21/154) of fetuses with normal UA Doppler assessment had an adverse perinatal outcome compared to 24% (4/17) of those with abnormal UA Doppler assessment, p = 0.28]. CONCLUSION: UA Doppler assessment is unlikely to predict adverse perinatal outcome in normally grown, euploid singleton fetuses with CHD.

Predictors of Poor Outcomes in Monochorionic Diamniotic Twin Pregnancies Complicated by Selective Fetal Growth Restriction.

INTRODUCTION: The aim of the study was to identify predictors of poor outcomes in monochorionic diamniotic twin (MCDA) pregnancies with selective fetal growth restriction (sFGR), irrespective of the umbilical artery (UA) Doppler abnormalities. METHODS: Single-center retrospective analysis of MCDA twins diagnosed with sFGR that opted for expectant management between 2010 and 2021. The presence of any of the following variables in the growth-restricted fetus: low amniotic fluid volume (DVP ≤2 cm), lack of a cycling bladder, absent or reversed flow in the ductus venosus (DV) with atrial contraction, and elevated middle cerebral artery peak systolic velocity (MCA-PSV) defined as ≥1.50 multiples of the median was categorized as complicated. sFGR cases were classified as simple in the absence of the above-mentioned variables. RESULTS: Overall, 63.3% of cases qualified as simple, and 36.7% were complicated. Intertwin EFW discordance was higher in the complicated category (26 vs. 33%, p = 0.0002). The median gestational age at delivery was earlier (33 weeks vs. 30.5 weeks, p = 0.002), and the likelihood of survival was lower in the complicated category (p < 0.0001). The likelihood of two survivors to discharge was lower in type I complicated cases (70% in complicated type I vs. 97.1% in simple type I, p = 0.0003). On logistic regression analysis, an increase in the "complicated" score negatively correlated with two survivors to discharge (p < 0.0001). An ROC curve was created, and the AUC was 0.79. Increasing intertwin EFW discordance also decreased the probability of two survivors to discharge. CONCLUSION: The presence of oligohydramnios, lack of a cycling bladder, abnormal DV Doppler, and elevated MCA-PSV in the growth restricted fetus is associated with poor perinatal outcomes and a lower likelihood of having two survivors to discharge. The addition of intertwin EFW discordance to these variables helped improve the survival predictability.